Surface properties of alkali silicate glasses: Influence of the modifiers.

Using large-scale molecular dynamics simulations, we investigate the surface properties of lithium, sodium, and potassium silicate glasses containing 25 mol % of alkali oxide. The comparison of two types of surfaces, a melt-formed surface (MS) and a fracture surface (FS), demonstrates that the influence of the alkali modifier on the surface properties depends strongly on the nature of the surface. The FS exhibits a monotonic increase of modifier concentration with increasing alkali size while the MS shows a saturation of alkali concentration when going from Na to K glasses, indicating the presence of competing mechanisms that influence the properties of a MS.

Roughness and Scaling Properties of Oxide Glass Surfaces at the Nanoscale.

Using atomistic computer simulations we determine the roughness and topographical features of melt-formed (MS) and fracture surfaces (FS) of oxide glasses. We find that the topography of the MS is described well by the frozen capillary wave theory. The FS are significant rougher than the MS and depend strongly on glass composition.

Structure and vibrational properties of sodium silicate glass surfaces.

Using molecular dynamics simulations, we investigate how the structural and vibrational properties of the surfaces of sodo-silicate glasses depend on the sodium content as well as the nature of the surface. Two types of glass surfaces are considered: A melt-formed surface (MS) in which a liquid with a free surface has been cooled down into the glass phase and a fracture surface (FS) obtained by tensile loading of a glass sample. We find that the MS is more abundant in Na and non-bridging oxygen atoms than the FS and the bulk glass, whereas the FS has higher concentration of structural defects such as two-membered rings and under-coordinated Si than the MS.

New interaction potentials for borate glasses with mixed network formers.

We adapt and apply a recently developed optimization scheme used to obtain effective potentials for aluminosilicate glasses to include the network former boron into the interaction parameter set. As input data for the optimization, we used the radial distribution functions of the liquid at high temperature generated by ab initio molecular dynamics simulations, and density, coordination, and elastic modulus of glass at room temperature from experiments. The new interaction potentials are shown to reliably reproduce the structure, coordination, and mechanical properties over a wide range of compositions for binary alkali borates.

New interaction potentials for alkali and alkaline-earth aluminosilicate glasses.

We apply a recently developed optimization scheme to obtain effective potentials for alkali and alkaline-earth aluminosilicate glasses that contain lithium, sodium, potassium, or calcium as modifiers. As input data for the optimization, we used the radial distribution functions of the liquid at high temperature generated by means of ab initio molecular dynamics simulations and density and elastic modulus of glass at room temperature from experiments. The new interaction potentials are able to reproduce reliably the structure and various mechanical and vibrational properties over a wide range of compositions for binary silicates.

Barriers to Disease Monitoring and Liver Cancer Surveillance Among Patients with Chronic Hepatitis B in the United States.

Chronic hepatitis B infection (CHB) is a condition that needs ongoing care such as monitoring for liver enzymes (ALT) and HBV DNA tests in treated and untreated patients, and annual imaging evaluation for liver cancer. Although follow-up care and treatment might seem straight forward, an estimated two-thirds of those who are aware of their infection are not seeing a health care provider, and more than half of those who are eligible for treatment do not receive it. This study aimed to compile and examine studies related to the barriers of disease monitoring, treatment, and liver cancer surveillance for CHB patients in the United States (US).

New optimization scheme to obtain interaction potentials for oxide glasses.

We propose a new scheme to parameterize effective potentials that can be used to simulate atomic systems such as oxide glasses. As input data for the optimization, we use the radial distribution functions of the liquid and the vibrational density of state of the glass, both obtained from simulations, as well as experimental data on the pressure dependence of the density of the glass. For the case of silica, we find that this new scheme facilitates finding pair potentials that are significantly more accurate than the previous ones even if the functional form is the same, thus demonstrating that even simple two-body potentials can be superior to more complex three-body potentials.

The Romanian Adaptation of the Survey Work-Home Interaction, NijmeGen.

To date, there are no scales measuring work-home interaction which are adapted for the Eastern European population. Owing to the significantly different sociocultural contexts and geopolitical history between Western and Eastern populations, despite the massive contemporary East-West migration, a more culturally appropriate scale is needed to ensure valid and reliable measurement of the construct. This article presents the adaptation of the Survey Work-Home Interaction-NijmeGen (SWING) for the Romanian population.

Amorphous silica modeled with truncated and screened Coulomb interactions: a molecular dynamics simulation study.

We show that finite-range alternatives to the standard long-range pair potential for silica by van Beest et al. [Phys. Rev.